The extent of lymph node dissection in early-stage non-small cell lung cancer: current controversies, evidence gaps, and future directions in the immunotherapy era-a narrative review.

BACKGROUND AND OBJECTIVE: The optimal extent of lymph node dissection (LND) in early-stage non-small cell lung cancer (NSCLC) remains a clinical dilemma. Although systematic LND is regarded as the gold standard, accumulating evidence from randomized evidence challenges its universal application, while the advent of sublobar resection and immunotherapy adds further complexity. This narrative review synthesizes current evidence, identifies controversies and gaps, and proposes directions for personalized LND strategies. METHODS: We systematically searched PubMed, Embase, and Cochrane Library (January 2000-December 2025) using terms related to NSCLC, LND, systematic/lobe‑specific dissection, sublobar resection, and immunotherapy. We included randomized controlled trials (RCTs), meta‑analyses, prospective cohorts, and propensity‑ score‑matched retrospective studies. Two authors independently screened and selected studies, with disagreements resolved by consensus. KEY CONTENT AND FINDINGS: Evidence comparing systematic dissection versus sampling is conflicting, with randomized trials showing no consistent survival benefit. Lobe‑specific LND offers comparable oncologic outcomes with lower morbidity in selected patients, but study heterogeneity limits conclusions. The debate over 4L station dissection in left‑sided tumors illustrates the sensitivity of meta‑analyses to inclusion criteria. The minimal acceptable nodal assessment for sublobar resection remains undefined. Emerging tools such as sentinel lymph node (SLN) mapping, radiomics, and molecular biomarkers show promise but are not yet routine. Preliminary immunological data suggest that extensive removal of non‑metastatic nodes may deplete tumor‑draining lymph node immune reservoirs, potentially compromising perioperative immunotherapy efficacy. CONCLUSIONS: A uniform LND strategy is unsupported by current evidence. A risk‑adapted, individualized approach integrating preoperative imaging, intraoperative pathology, and immunological considerations is warranted. Priority research areas include defining LND thresholds for sublobar resection, validating sentinel node techniques, and clarifying the interaction between LND extent and immunotherapy response.